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Bioavailability Enhancement

Oral bioavailability enhancement

Formulating with lipid excipients is a viable strategy for enhancing the oral bioavailability of poorly water soluble API. It is particularly appropriate for Class II API and may offer a solution for some Class III and Class IV compounds.

There are 2 main types of formulations that can be developed using Gattefossé excipients to improve oral bioavailability - oily formulations and surfactant formulations.

The role of lipid excipients

Lipid excipients play three fundamental roles in both oily formulations and surfactive formulations:

  1. Disperse/solubilise the API in the dosage form
  2. Facilitate emulsification of the API upon contact with gastrointestinal fluids
  3. Maintain the API in a solubilised form during gastrointestinal transit thereby increasing absorption.

Oily formulations

  • Simple formulations for use when the API is completely solubilized in an oily vehicle.
  • Appropriate for very lipophilic API (logP > 5), which are readily solubilised in low HLB excipients.
  • Liquid and semi-solid formulations are appropriate for soft and hard gelatin capsules.
  • Suitable excipients: Maisine 35-1, Peceol, Labrafac Lipophile WL 1349, Labrafac PG - see Solubility and bioavailability enhancement

Surfactant formulations

Surfactant formulations include any single lipid excipient with surfactant properties (e.g. Gelucire 44/14 or Labrasol), which can be used in a simple binary self emulsifying formulation; or multiple excipients formulated into SEDDS (Self emulsifying drug delivery systems) or SMEDDS (Self microemulsifying drug delivery systems).
  • Applicable when surfactant power is required to solubilize the API in aqueous systems.
  • Able to rapidly and spontaneously form fine oil-in-water emulsions or microemulsions on contact with gastrointestinal fluid
  • Particularly useful for drugs that are poorly or irregularly absorbed and/or show food dependant absorption patterns
  • Liquid, semi-solid and powder formulations can be filled into hard gelatin capsules. Additional ingredients can be added to powders for tabletting
  • Suitable excipients: surfactants, co-surfactants, oily vehicles - see Solubility and bioavailability enhancement

SEDDS and SMEDDS

SEDDS and SMEDDS are powerful formulation tools for poorly water soluble API. They have been successfully used to improve the oral bioavailability of a number of commercially available drugs.

Straightforward to manufacture, SEDDS and SMEDDS are physically stable mixtures of oil, surfactant, co-surfactant and API. Upon contact with aqueous media or intestinal fluids, SEDDS and SMEDDS readily form characteristic small emulsion particles.

  • SEDDS produce opaque dispersions with droplet sizes ranging from 200 nm to 5 μm
  • SMEDDS result in translucent microemulsions with particle sizes < 200 nm

Using its extensive expertise in the development of SEDDS and SMEDDS Gattefossé has created the SELF Kit to speed up the process of developing a suitable SEDDS or SMEDDS for your API. For further information see Formulation guide - SELF Kit

Technical support

Please contact us or complete an enquiry form to request:

  • Product samples
  • Gattefossé’s Lipid Excipients for Oral Bioavailability Enhancement brochure
  • Further product handling, regulatory and toxicology information
  • Details of the technical services offered by Gattefossé’s Application Laboratory

For Gattefossé’s full range of lipid excipients for solubility and bioavailability enhancement see Solubility and bioavailability enhancement